Telephonic apparatus.



E. A. GRAHAM.

TELEPHONE APPARATUS. APPLICATION EILED OOT. 7, 1907.

Patented July 20, 1909.

11 SHEETS-SHEET 1 E.'.A. GRAHAM. TELEPHONIG APPARATUS.

APPLICATION FILED 0017,1901

Patented July 20, 1909.

11 smm's snnz i 2.

A. GRAHAM.

TELEPHONIG APYARATUS.

APPLICATION FILED OCT. '7, 1907.

Patented July 20, 1909.

E. A. GRAHAM. v TELEPHONIG APPARATUS.

- APPLIGATION FILED 0017. 1907.

"E. A. GRAHAM. I

TELEPHONIC APPARATUS. APPLICATION FILED oo'r 7. 1907.

Patentd July 20,1909.

u SHEETS-SHEET 5.

mw a'a 50A;

E.' A. GRAHAM. TBIQEPHONIG APPARATUS.

.A PPLIGATION FILED OUT. 7. '1907. Q

Patented July 20, 1909.

B. A. GRAHAM. TELEPHONE! APPARATUS.

APPLIGATIOK FILED OCT. 7, 1907.

928,862. Patented July .20, 190

11 SEEETB-SHEET 7.

E. A. GRAHAM.

Patented Jfily 20, 1909 0 -9 S1 UI T7 A B Aw ND. AW mm m HI T A Lw L P P A 11 SHEETS-SHEET 8,

E. A. GRAHAM.

TELEPHONIG APPARATUS.

- APPLICATION FILED OUT. 7, 1907.

Patented July 20, 1909.

flaunts-SHEET 9.

Wm, /WM,

EJA'IGRAHAM. TELBPHONIG APPARATUS.

APPLICATION FILIIID OCT. 7, 1907.

Patented July 20, 1909.

11 SHEBTS-SHEET l0.

E. A. GRAHAM.

TELEPHONIO APPARATUS.

APPLICATION FILED OUT. 7. 1907.

Patented July 20, 1909.

ll SHEETS-SHEET 11.

more; si s PATENT osi re.

EDWARD ALFRED GRAHAM, or nRocKrlsY, Lennon, ENGLAND, ASSIGNOR ro HIMSELF AND A L FRED GRAHAM a co, or BROCKLEY, ENGLAND.

- vented Improvements in TELEPHONIC APPARATUS;

Specification oi Letters Patent.

Patented July 20, 1909.

Application filed October 7, 1907. Serial No. 396,276.

To all whom it may concern:

Be it known that I, EDWARD ALFRED GRAHAM, a subject of the King of Great Britain and Ireland, residing at Brockley, in

the county of London, England, have inratus, of which the following is a specifics: tion.

This invention has reference to improvements in telephonic apparatus of the kind in WlliCl'l the telephonic transmitter and receiver and the switch and electrical connections are mounted in a stationary casing, and it has for object to improve the construction and working of such apparatus; to enable the cas ing to be readily maintained in a perfectly water tight condition; to render the internal parts of the apparatus readily accessible; to

enable the fluctuations set up by the trans mitter of one telephonic instrument to be reproduced with full effect in the receiver of another telephonic instrument, irrespective of the'value of the inductance in the circuit,

Whether inherent therein or purposely in-" sorted, so that objectionable extraneous iiuc- 'tuations can be rendered practically inapprociable in the telephone apparatus and to mini mize the transmission of mechanical shocks to the apparatus from the support to which the same is attached. For these purposes the apparatus is constructed as will nowbe described with reference to the accompanying drawings whereini Figure 1 is a front view, F ig. 2 an underside view and F ig. 3 a horizontal section on the line A A of F ig. 1, as seen from below, showing one construction of telephonic apparatus embodying the invention. Fig. 4 is a front view of the apparatus with removed and part broken. away. Fig. 5 is an inverted rear view of the cover with the parts carried thereby. Fig 6 is a face View of a rotary carbon elcctrodeforming part of the transmitter. Fig. 7 is a face view and Fig. 8 a'horizontal.cross section-on the line B B of Fig. 7, showing a modified construction of transmitter. Fig. 9 is a horizontalsection' showing a further modified construction of transmitter. lii 10 shows in rear-elevatlon, and 1 1g. 11 in section on the hue C not Fig. 10, part of the telephonic receiver tached from the apparatus. Figs. 12am a... are respectively front and side. elevations and 14 a vertical section on the lineD D of F 12, showing a modified construction Telcphonic Appathe cover 7 of the apparatus. Fig. 15 is a diagram showing how two of nients can'b e connected up for use. in is a diagram showing a modified arrange ment of the electrical connections.

In telephonic apparatus of the kind referred to, 1t has been usual to em by a transmitter of the micro hone or car on granule type and to-mounttlie holder or case cal'rying such transmitter on the inner side of the stationary frontcover of the casing, and to provide means whereby the holder and transmitter can be rotated from time. to time in order to shake up the carbon granules therein and thereby maintain the transmitter in 00d working order. This arrangement however has rendered it necessary to form between the cover and bolder, a movable joint'which it has been found (.liflicult in practice to keep perfectly water ti ht, so that when the apparatus is used on )oard ship and in other exposed positions, for which use the apparatusis more particularly designed, moisture is liable to enter the casing and affect the switch and other electrical connectrons therein and thus prevent the apparatus being maintained 1n good working COINlItIOH for long intervals withoutattcntion.

Now according to the present invention in order to avoid this disadvantage, the holder a containing a transmitter of the kind re-.

ferred to is permanently fixed, as by screws, in or over an opening I) in the front cover a of the telephonic casing (I so that a perfectly water tightjoint is made between the two,

and means are provided whereby the carbon granules e in the'transmitter can be agitated by movement of a body in direct contact therewith and arranged to be actuated from within the casing d either automatically in the act of erforming some other necessary telephonic Function, or independently, as by a hand operated device ca able of being actuated from the exterior o the casing. The

granules e may conveniently-be confined as shown, between the central portion of a stationary front insulated carbon electrode or diaphragm f anda rotary rear carbon electrode g, or cup g, fixed to a spindle k that extends through the rear wall a of the holder a and is provided with wheel 7: adapted to be rotated by a toothed segment at capable of being operated from outside theeesing d. The front face of the carbon block g, or the inner surface of the cup 9, or

the telephonic instruw aegeach of these parts when both are movable, as in the example shown in Figs. 3 and 6, 15

or may be formed with pyramidal, conical c-r'like recesses or projections g, or be otherthe kind referred to, or be otherwise adapted on one or both sides for the purpose men tioned. Or, as shown in Figs. 7 and 8, the device may consist of vanes 71 of mica attached to a rotary spindle h. Or, as ghown in Fi 9, the granules e may be agtated both by a rotary carbon electrode and cup g g and a rotary agitatin device i formed and arranged as described and adapted to be rotated in the sameor op osite directions. in Fi 9 the spindles h and 1 are concentric and t e spindle h is provided with a toothed wheel 7c and the spindle h with an internally toothed wheel is} into which gears a pinion k that also gears into the toothed wheel k.

The shaft 71 is also provided with a toothed wheel 76* adapted to be rotated by a toothed segment m operation of which will turn the spindles and attached parts" simultaneously in opposite directions.

The granules 0 may be retained in place between the cup 9 and diaphragm f by soft packing material n, for example a ring of cotton, wool or the like. The rotary agi: tating portion or portions of the transmitter may conveniently be operated through gearing from the movable part of the switch used for opening the bell'circuit and putting the receiver and transmitter in circuit and vice versa, as hereinafter described. The dia-- phragm f is preferably covered by metal foil 0, as usual, secured in a water tight manner, as by soldering at its outer periphery to the outer portion of the holder or. The dia phragm is preferably protected by a metal grating carricdby a metal ring 1' that is iixed to the coverc and is preferably adapted to form, as shown, a mouthpiece r to which the grating g is fixed. r is a ring fixed to the outer side of the holder a se as to surround the mouthpiece 1" andpartly overlap the diaphragm f. The rings 1 and r are formed at their lower portions with openings 1"? (Fig. 2) for escape of any water that may enter the space between the diaphragm f and grating g.-

'.l.hc permanent magnet t of the telephone receiver ism-ranged in the rear end portion of the telephone casing (Z with its diaphragm u opposite a sound aperture, tube or passage '1:

which extends through the rear end wall (1 -USB.

of the casing and is in communication with a hearing tube or trumpet 'w. This tube or trumpet is preferably so mounted as to be capable of being turned about a horizontal axis to bring it into a convenient position for Sometimes, as in the example shown in Figs. 12, 13 and 1.4, the said sound aperture, tube or passage tie in communication with two normally depending movable hearing tubes w, to having ear-pieces w of known kind; The metal casing a is preferably divided by a wall or partition (i into two separate compartments, namely a rear compartment 1 in which the telephonic receiver is placed, and a front compartment 2 iii-which the telephonic transmitter, switch and various electrical connections are arranged. The switch is preferably mounted on the inner side of the cover 0 which is either hinged to or completely detachable from the casing so as to enable ready access to be gained to the interior thereof for inspecting the va.

rious parts therein.

Thevarious electrical connections between the transmitter, receiver, line wires and telephonic bell, are preferably made through two sets of contacts, viz. a'iixed set indicated collectively at 4 in Fig; 4, and a movable set, indicated collectively at 5 in Fig.5, the fixed set 4 of contacts being secured to a stationary insulating support 6 in the front chamber 2, and the movable set 5 being secured to an insulating support 7 at tached to the inner side of the cover a. The two sets of contacts are so arranged that they will automatically make proper conneccome detached from each other, without injury, when the cover is opened. By this means, ready access can be gained to all parts of the apparatus when the cover a is turned back or removed.

To enable the casing d to be readily closed in a'water tight manner, the cover 0 is provided on its inner side with a packing ring 8 of india rubber or equivalent material in which the front edge i of the casing will be embedded when the cover is secured in place.

In order that the fluctuations set up by the transmitter of one telephonic instrument may be reproduced in the receiver of another telephonic instrument with full ef fect,. irrespective of the value of the inductance in the circuit, whether inherent therein or purposely inserted, so that objectionable extraneous fluctuations can be rendered practically inappreciable in the telephonic apparatus, especially in cases where the telephonic apparatus isjworked from electric supply' mains fed from' a dynamo-electric machine, (a resistance 9 tion with each other when the cover 0 is se- .cured to the casing d, and will readily besuch a manner that a transmitter take place, without larger diameter be securely erases phone switch, as hereinafter more fully de scribed, in parallel with the circuit, or portion of a circuit, which includes the trans 'mitter of one telephonic instrument and the receiver of another telephonic instrument in and receiver circuit the inductance and in which fluctuations, or certain. of the fluctuations occasioned by the telephonic instrument, take place, or may necessarily traversing the inductance containing portion of the circuit.

To prevent or minimize the transmission of shocks to the telephonic apparatus from the bulkhead or othersupport therefor, the casing of such apparatus may be supportedor connected to such bulkhead orsupport in a more or less elastic or yielding manner.

The various portions of telephonic apparatus embodying the present invention can be constructed in various forms.

in the constructional form. shown in Figs. f 1 to 6 inclusive,

the casing (Z is of cylindrical shape, the front portion thereof being of than the rear portion so as to form between them an internal annular shoulder it) against which the partition d which forms a cover for the rear compartment 1, is detachably fixed, as by screws-11.

The cover 0 is hinged at oneside to thecasing,

d at d so that it can be freely turned outward to one side thereof, and is adapted to fixed in the closed position to the casing, as by screws 12 passing through lugs l3 formed on it and engaging lugshl on the casing. 4

The telephone transmitter cf 9 is constructed with an agitating device, and its holder (2 is fixed to the cover 0, as hereinbefore described.

The telephonic receiver (Figs. 3, 4, 10 and 21) comprises the diaphragmu and a curved powerful permanent magnet 2 having polar projections t that are arranged at rightangles to andopposite the central portion of the diaphragm u and around which are the receiver coils t fas heretofore usual. In order however to avoid the transmission of strains to the diaphragm when the said magnet t is fixed in place, the diaphragm holder 16 and magnet are pendently of each other, the diaphragm holder being fixed to the rear wall d of the casing d opposite the centrally arranged sound aperture v therethrough, and the magnet if being fixed to the inner side of the removable front cover (Z of the rearv c0m partment 1.

.To enable the pole pieces a to be readily adjusted in relation tothe diaphragm u, so as to enable the best telephone sheets to be obtained, they are preferably made so arately adjustable in anendwisb. direction is established which excludes the permanent the proper position in which it arranged indein relation to the magnet so thateach of them can be easily and quickly adjusted toward or from the diaphragm to cause it to assume the proper position to obtain the,

best results, In the arrangement shown for 70 this purpose, the permanent magnet t is made of flat annular shape with a radial slit 17 therethrough at one part To the free ends of the ring are fixed two pieces of soft iron 18 that 7 center of the magnet and form polar extens sions of the magnet. To the free eiid of eachof these polar extensions 18, and at right angles thereto, is fixed the flanged end ofa short soft iron tube 19. provided at its ends with rings or collars 20 of non-magnetic material, for example brass, or vulcanized fiber, so as to form a spool for carrying one of the receiver coils t Each tube 19 is screw threaded internally and as provided with a projection t adapted, as admit of its screw driver, in the tube.

screw threaded'pin or polar by forming it with a notch, to being readily rotated, as by a magnet t with attached parts has been rigidly fixed in place, each pin t can be easily and quickly adjusted in an endwise direction in the tube 1 from the diaphragm u, to cause it to assume can be then fixed, as by a locknut It". To enable ready access to be gained to thoadjustablc' pole pieces the cover (I may be formed aperture 21 normally closed detachable cover y be held at its periphery u may convenient between rings 16 0t India rubber'or like by a hinged or late 22. The diaphragm material clamped between the rear wall d of the casing of and an annular metal holder 16 secured thereto by screws 16".

Over the'sound exit aperture 4) is secured the bent inner end we of a radially arranged speaking tube to that is capable of being 1110 turned about a horizontal axis and the outer end 10 of which is of flared or trumpet shape and arranged to extend in a forward (lirec tion. The end w of the said tube may conveniently be jointed to the casing (Z by forming it with an outwardly extending flange '20 that is held in a socket23 in the rear wall (2 of the casing by part of a slotted ring 24 that is fixed to the said rear wall and overlaps the flange so as to allow of the tube be ing turned to bring the speaking trumpet 11; into any convenient position for use The switch for putting the'bell out of cir-,

cult and the transmitter and receiver in circuitand vice versa coin rises accordin to the construction shownm Fig. 5, six fixed contacts 8, s s s, s and s", which are fixed upon a base 25 of insulating material fixed to the inner side of the front cover 0, and two pairs o'fniovable contacts s, s and s, s

extend inwardly toward tlfe 75 This tube is so of softiron one end of which is to cause it to moveendwise 90 13y this arrangement, after 9 toward or 95 'ith an 100 [quadrant shaped frame 26.

is fixed to a spin which are carried by but insulated. from a This frame works in a plane parallel to the cover 0 and 28 and extending in a practically watertight mannerthrough the cover to the front side thereof where it is provided with a hand lever 27 a (Fig. 1) which has an extension 27 arranged to work between two fixed sto s 27 Tlhe arrangement is such that t e' frame 26 can be partly rotated by the lever 27 against the action of a spring, suchasaranged concentrically to the switch spindle 27, contacts s and 8 being arranged in one circular arc of one radius and insulatedfrom each other, and contacts .9 and s and s and 8 being arranged in another circular arc of a different radius and insulated from each other. The movable contacts 3 and s are arranged side by side and electrically connected together, contact 87 being arranged to hear at all times upon contact 8- and contact 3 being arranged to normally bear upon contact 8 but to slide over it and bear against contact 8 when the switch spindle 27 is rotated against the action of the spring 27 The movable contacts s and 8 are also arranged side by side and electrically connected, contact s 'bearing at all times upon contact sfland contact s normally bearing upon contact s 'but arranged to slide over the same and bear against contact s when the switch spindle 27 is moved against the action of the spring 27. The electrical connections. between the switch and the transmitter, receiver, line wires and bell comprise, according to the arrangement shown in Figs. 4, 5 and 15,- a set of insulated movable'contacts 5 5*; 5, 5 5 and 5 in the form of pins, and a set of. corresponding insulated fixed contacts 4, 4 4, 4 4

and 4 in the form of pairs of spring blades between which the contact pins will pass and against which they will bear when the cover 0 is closed. To the rear side of the cover 0 are fixed two insulated terminals 30 and 31 that are connected to the stationary and roe 27 carriedby a bearing shown.

was;

veniently be a lever arranged to be operated by the push 36 and carried by a metal support 37 having a terminal .38. The fixed switch member 33 has a terminal 33. To

prevent orminimize arcing, the two members the insulating block 6 are also fixed two ter. minals 39 and 40, and upon the front side of the cover (1 but insulated therefrom, are fixed four terminals 41, 41, 42 and 43 whereof 41 and 42 are connected (see Fig. 15)

to the two ends of the-connected coils t of the telephonic receiver. The terminals 41 and 41 are, in ordinary use, connected as The terminals 41 and 43 are connected to the two ends of the non-inductive resistance 9. minals are connected up as follows (see Fig. 15). Contact 8 is connected to contact 5; contact 8 to hell terminal 38; contact 8 to contact 5 and transmitter terminal 30; contact s to cont-act '5 contact s to contact 5; contact 8 to'contact 5; contact 5 to the transmitter terminal 31 and bell terminal 33; contact 4 to the receiver terminal 42, and contact 39 to terminal 41. Contacts 4', 4, 4 and 39 are connected respectively to separate insulatedconductors 44, 45, 46 and 47, and contact 4 to a conductor 48. Contact 39 is also connected to another conductor 49. The several conductors are led, in the form of a cable, and in aWater-tight manner, through a gland50 (Fig. 2) in the lower side of the front chamber 2. The conductors 44, 45, 46 and 47 are connected througha fuse and terminal box, or through a switch board at a central station, to another telephonic instrument at a distance and to an electric generator or generators,

and conductors 48 and 49 are connected to the telephone bell B in an ordinary manner.

In the example diagrammatically shown in Fig. 15, the two conductors 44 of two tele- The various contacts and terv phonic instruments T and T constructed as described are each connected to a ositive terminal 51 in a fuse and terminal ox 5,2, the said terminal being connected through a line coil 53, terminal 53, fuse 54 and termi nal 55 to. the positive terminal of an electric generator 56. The conductor 45 from the instrument T and the conductor 46 from the instrument T are connected to a common terminal 57. The conductor 46 from the instrument T and'the conductor 45 from the instrument T are connected to a common terminal 58, and the conductors 47 from both instruments are connected to a negative terminal 59 which is connected to the negative pole of the electric generator 56. The arrangement is such that when the cover 0012' each mstrument is closed and the switch is in '5 36 of instrument T be '10 through the parts 46, 4 5, s 8, s, s", 5, 4, bell B, 49, 39 and 47 of instrument T to the 25 strument '40 terminal 5 9, for

65 the several parts are slightly ceases its normal position, the telephonic -trans mitter and receiver are out of circuit but the bell of either instrument can be rung up from the other station. For example, if the push o .erated to ring up the bell B of instrument the circuit will be from positive terminal 51, through the parts 44, 4 5 8 8 s s 38, 34, 33 in, 5- 4 and 45 of instrument T to terminal 58, then negative terminal 59. W hen the switches of the two instruments are operated by their hand levers 27" to speak, the two bells will be cut out of circuit and the transmitter of each instrument put in circuit with the receiver of theother instrument. The circuit of the transmitter of instrument T and the receiver of instrument T is as follows :from

positive terminal 51 through the parts 44, 4",

5*, s, s s s transmitterf, g, 31, 5, 4" and conductor 45 of instrument T" to terminal 58, thence by the parts 46, 4, 5, s, s", e, s, 5", 4", 42, receiver 41, 39, and 47 of in- T to the negative terminal 59. The circuit ofthe transmitter of instrument T and the receiver of instrument T is as followsz-lrOm positive terminal 51 through the parts .44, 4 5", 8, 8 s", s, 30, transmitterf, g, 31, 5", 4, 45 of instrument T to terminal 57, then by the parts 40, 4, 5, s, 8, 8 8, 5", 4, 42, receiver R, 41, 39 and 47 to the negative terminal 59. The end of the resistance 9 in each instrument is at the same time connected through the parts 43, 4, 5

to s and consequently to the positive terminal 51, while the other end of the said resistance is connected through the parts 41 and 41 to 39 and consequently to the negative the purpose hereinbcl'ore described.

Thcelectri cal connections of the telephonic instrument can be varied to suit different requirements. 'Thus Fig, 16 shows an ar- 5 rangement in which the left hand telephonic instrument T, which may be for use at-a cen tral station, is adapted to ring up and speak "to a second instrument T at an outstation the telephonic receiver of which is in circuit 0 and will reproduce speech without operating the switch of such instrument, and a person at the outstation can speak to the c ntral station when the switch at that station'has been operated but cannot ring up such station. in this-case contacts 4 and 5 of Fig. 15 are omitted in the central station instrument T and their p ositioi'i occupied by the coi'itac'ts 4, 5; the parts s", 8", s, s" and s" of the switch are also omitted, and the bell switch lever 34 normallybcars against a contact 34* that is connected to contact 5;

44,4", 5*, s,s ,s ,s 30, transmitter f, g, 31, 5, 4, and 45 of instrument T to terminal 57 and thence through the parts 46, 4, 42,'receiver coil, 41, terminal The operator at station T can, after 0 ment 1 through the following circuit 1- fronrpositive terminal 51 through the parts 44, 4", 5, S, S, S, S, 39, transmitterf, g, 31, s, s, e", s, 5, 4 and 459i instrument T to terminal 58 and from thence through the parts 46, 4 5,-." 8, 34, 34 5 4 42, mceiver coil 1 41, 39 and 47 of instrument 'l to negative terminal 59. p

'lhe'switch frame 26 may, as shown, carr the toothed segment m that the toothed wheel 7r fixed to the spindle h of the rotary electrode 9 or equivalent agitating device of the transmitter, so that each time the said switch frame is operated, the said electrode, or equivalent; V the carbon granules e of the transmitter agitated. The non-inductive resistance de' vice 9 may, when used for the purpose hereinbel'ore mentioned, conveniently be lixcd in the rear chamber 1, of the casing (l, as for example to the rear side of the cover plate (1 thereof, and around the permanent magnet t, and has its two ends connected to ter-v ject to stress or strain when in use in cold climates.

. 1n. the modified construction shown in Figs. 12, 13 and 14, the sound aperture 1) in the rear end walla" is connectedto a transverse sound passage to to the opposite end of which are attached tubular fittings w that can turn about an axis corresponding to the line 1) 1) of Fig. 12, and to which the two depending hearing tubes to, of with. car pieces 10 are articulated, the arrangement being rotated around the axis of the said fittings In the out-station instrument T, cmtacls 5, 4 and 5" of Fig. 15 are omitted. Also, 111 both instruments the connections between modified. as

-.so as to avoid any possibility cithe instru ment being injured by such rotation, In this case, the switch frame 26 is provided with a laterally extending lever arm engaged by the forked end 61 of a let er G1 pivoted The operation in this case is as to The operator .at'station through the parts a 39 and 47 to the negative.

is in gear wit r )erating his switch, speak to instru I *ill be rotated and such that the said tubes can be freely i'se ' tubular fitting w, so thateach time the corcont aininga transmitter 0 responding hearing tube w is raised into positionfor use, the lever 61 will operate the switch frame 26 and attached parts, and the segment thereon will operate the rotating carbon electrode g of the transmitter, as and for the purposes hereinbefore described.

To minimize the transmission of shocks to the telephonic instrument from its support, the rear end wall d of the casing (Z may be formed with hollow lugs 65 in which are fitted sup orting pins 66 adapted, as by lugs 67-, to be xed to the said support, a coiled spring 68 being interposed between the inner end of each pin and the casing for the purpose mentioned.

The details of construction can be variousl modified. I

Vi at I claim is v I i ll Telephonic apparatus comprising a stationary casing having a water tight door and containing a transmitter of the carbon granule type, a receiver, and a switch adapted to control the circuits of said transmitter and receiver and of being operated from the exterior of the casing, a holder rigidly fixed in a water tight manner in an opening in said door and in which said transmitter is fixed, said transmitter having a movable part constituting an agitating device in contact with the carbon granules in said transmitter, an operating device connected to said movable part of the transmitter and extending into said casing and means whereby said operating device and agitating device can be operated from the exterior of the casing.

2. Telephonic apparatus comprising a stationary casing having a W ter tight door and i the carbon granule type, a receiver, a switch adapted to control the circuits of said transmitter and receiver and to be 0 )erated from the exterior of the casing, a holder rigidly fixed in a water tightmanner in an opening in said doorand in which said transmitter is fixed, said transmitter having a part adapted to form a retary granule agitating device in contact with the carbon granules in said transmitter and extending into said casing, means located within said casing for rotating said agitating device and means whereby the said rotating means can be operated from the exterior of the casing.

3. Telephonic apparatus comprising a stationary casing having a Water tight door and containing a transmitter of the carbon granule type, a receiver, a switch adapted to control the circuits of said transmitter and'receiver and tojbe o erated from the exterior of the casing, a 1101 er rigidly fixed in a water tight manner in an opening in said door and in which said transmitter is fixed, said transceases mitter having a movable part constituting an agitating device in contact with the carbon granules in said trannnitter and provided with an operating device extending into said casing and means for operating said agitating device from said switch l. Telephonic app aratus'coniprising a st.- tionary casing having a water tight door and containing a transmitter of the carbon granule type, a receiver, a switch for controliing the circuits ofsaid transmitter and receiver, said switch being adapted to be operated from the exterior of the casing, a holder rigidly fixed in a water tight manner in an opening in said doorand in which said transmitter is fixed, said transmitter comprising a stationary front carbon electrode, a movable rear carbon electrode and carbon granules confined between the rear electrodes and the central portion of the front electrode, a spindle fixed to said rear'electrode and means extending within said casing whereby said spindle and rear electrode can be rotated from the exterior thereof.

5. Telcphonic appara tus comprising a stationary casing having a water tight door and containing a transmitter of the carbon gran 'ulc type, a receiver, a switch for controlling the circuits of said transmitter and receiver, said switch being adapted to be operated from the exterior of the casing, a holder rig idly fixed in a water tight manner in an opening in said door and in which said transmitter is fixed, said transmitter comprisinga stationary front carbon electrode, a movable rear carbon electrode and carbon granules confined between the rear electrode and the central portion of the front electrode, a spindle fixed to said rear electrode and meansior operating said spindle and rear electrode from said switch.

6. Telephonic apparatus comprising a staticnary casing having a water tight door and containing a transmitter of the carbon gran ule type, a receiver, a switch for controlling the circuits ofsaid transmitter and receiver,

said switch being mounted onsaid door and part of said switch.

7. Telephonic apparatus comprising a sta tionary casing having a water tight door and containing a transmitter of the carbon gran ule type, a receiver, a switch for controllingthe circuits of said transmitter and receiver, said switch being adapted to be operated from the exterior of the casing, a holder r1gidly fixed in a Water tight manner in an open 139 ceases ing in said door and m which said transmitter is fixed, said transmitter comprising a stationary frontcarbon electrode, a movable die fixed to said rear electrode for rotating the rear carbon and agitating the carbon granules, asecond carbon granule agitating device embedded in the granules and con.-

nected'to a spindle extending through the rear carbon and its spindle and gearing for rotating said agitating devices in opposite directions from said switch.

. 8. Telephonic apparatus comprising a cas-' mg, a removable partition dividing the same into separate transmitter and receiver compartments, a Water tight cover for the trans mitter com artment, a holder rigidly fixed to and exten ing through said cover, a microhone transmitter carried'by said holder and aving a part thereof adapted to form a granule agitating device extending from the transmitter into the transmitter ment and means adapted to be oierated from Without the casing for controlling the action of the agitating device.

9 Telephonic apparatus comprising a casing, a removable partition dividing the same into separate transmitter and receiver compartments, a water tight cover for the trans mitter compartment, a holder rigidly fixed to and extending through saidcover, a microphone transmittcn carried by said holder and having a part thereof adapted to form a granule agitating device extending from the transmitter into the transmitter compartment, means adapted to be operated from without the casing for controlling the action of the agitating device,-a receiver located in the receiver compartment and a sound amplifier in communication with said receiver.

10. Telephonic apparatus comprising a casing, a Water tight cover therefor, a holder fixed to and extending in a water tight manner through said coverfa transmitter within;

said holder, a removable partition dividing the said easing into a transmitter compartment and a separate receiver compartment, a receiver located in the receiver compartment and a sound trumpet communicating with said compartment, said sound trumpet being adjustable in a vertical plane about a horizontal axis extending from front to back of said apparatus.

11. Telephonic apparatus comprising a casing, a water tight cover therefor, a transmitter fixed to and extending through said cover, a removable partition dividing the said easing into a front compartment and a separate'rearcompartment, fixed and movable sets of contacts in the front chamber for establishin connection between the. transnutter, receiver, line Wires and telephon c of the casing. I

compart= ,same into separate front bell, and a receiver in the 12. Telephonic apparatus comprising a casing, aremovable Water tighf; covertherefor, a transmitter of the carbon granule type fixed to and extending in a water tight man ner through said cover, a removable partition dividing the said casing rear compartment ,j-nt-o a front compart-- ment and a separate rear compartment, a set of contacts stationarily carried by the re movable partition on the side adjacent to the front chamberand a co-acting set of contacts on the inner side of the cover arranged to automatically make connection with the other set when the cover is closed and become disengaged when the cover is opened. l8. Telsphonic apparatus comprising a casing, a removable water tight cover therefor, a transmitter of the carbon granule type fixed to and extending in a water tight manner through said-cover, a removablepartition dividing the said easing into a front compartment and a separate-rear compartment, a set of contacts stationarily carried by the removable partition on the side adjacent to the front chamber, a co-acting set of con tac ts on the inner side of the cover for engage-- ment and disengagement with the other set, areceiver in the rear compartment,- a sen-- tral aperture in the partition to enable partial access to be gained to the receiver when the front compartment is opened. and means for normally closing said aperture.

14. Telephonic apparatus comprising a.

casing, a removable partition dividing the same into separate transnntter and receiver compartments, a Water tight cover for the V transmitter compartment, a holder rigidly fixed to and extending through said cover, a

imicrophone transmitter carried by said holder and having apart thereof adapted to form a granule agitating device extending from the transmittervinto the transmitter compartment and means operated from without the casing forcontrol ling the action of the agitating device.

15. 'lelephonic apparatus comprising a casing, a removablepartition dividing the same into separate front transmitter and rear receiver compartments, a Water tight cover for the transmitter compartment, a

granular microphone transmitter extending partly through the saidicover andhaving part thereof adapted to form a granule agitating device extending from the transmitter into the. transmitter compartment, means for operating said agitating device from the exterior of said casing, a receiver lecatedin the rear compartment and a sound trumpet communicating with the said rear compartment and adjustable in position with respect thereto.

16L Telephonic apparatus comprising a casing, a removable partition dividing the transmitter and rear receiver compartments, a water tight cover for the transmitter compartment, a granular microphone transmitter extending partlvthrough the said cover and having part thereof adapted-to form a granule agitating device extending from the transmitter into the transmitter compartment, means for operating said agitating device from the exgranular microphone transmitter extending partly through the said cover and having part thereof adapted to form a granule agitating device extending from the transmitter into the transmitter compartment, means for operating said agitating device from the exterior of said casing, fixed andmovable sets of contacts in the front chamber for establishing connect on between the transmitter, receiver, line wires and telephone bell, a receiver in the rear compartment and a sound trumpet communicating with the rear compartment and adjustable with respect thereto about a horizontal axis.

18. Telephonic apparatus comprising a casing-a removable partition dividing the same into separate frontytransmitter and rear receiver compartments, a water tight cover for the transmitter compartment, a granular microphone transmitter extending partly through the said cover and having,

part thereof adapted to form a granule agitating device extending'from the transmitter into the transmitter compartment, means for operating said agitating device from the exterior of said casing, a set of contacts station-r arily carried by the removable partition on the side adjacent toithe front chamber and.

a co-acting set of contacts on the inner side of the cover arranged to automatically make connection with the other set when the cover is closed and become disengaged when the cover is bpened.

19. Telephonic apparatus comprising a casing, a removable partition dividing the same into separate front transmitter and rear receiver compartments, a water tight cover for the transmitter compartment, a granular microphone transmitter extending partly through the said-cover and having part thereof adapted to form a granule agitating device extending mitter into the transmitter compartment, means foroperating said agitating device from the exterior of said casing, a set of contacts stationarily carried by the removable partition on the side adjacent to the front from the transchamber, a co-acting set of contacts on the inner side of the cover arranged to automatically make connection with the other set when the cover is closed and become disengaged when the cover is opened, a receiver located 1n the: rear compartment, and a sound trumpet communicating with the said compartment.

20. Telephonic apparatus comprising a casing, a removable partition dividing the same into separate front transmitter and rear receiver compartments, a water tight cover for the transmitter comp art1nent,'a granular microphone transmitter extending partly through the said cover and having part thereof adapted to form a granule agitating device extending from the transmitter into the transmittercompartment, means for operating said agitating device from the exterior of said casing, a set of contacts stationarily carried by the removable partition on the side adjacent to the front chamber, a coacting set of contacts on the inner side of the cover for engagement and disengagement with the other set, a receiver in the rear compartment, a central aperture in the partition to enable partial access to be gained to the receiver when the front compartment is opened, and means for normally closing said aperture. 4

21. In telephonic apparatus, the combmation with a casing, a water tight cover therefor and a removable partition dividing the casing into front and rear compartments, of a permanent magnet fixed to the rear side of the partition, a diaphragm holder fixed to the rear end wall of the rear compartment and hearing means in communicationwith such compartment.' g;

22. In telephomd apparatus, the combination with a casing, a watertight cover therefor and a removable partition dividing the easing into front and rear compartments, of a permanent magnet fixed to the rear side of the artition, soft iron polar extensions exten ing toward the center of the magnet, an internally screw threaded soft iron tube carried hy each of said extensions, an externally screw threaded polar projection of soft iron carried within each tube, receiver coils supported by said tubes, and a diaphragm secured to the Wall of the rear compartment opposite the partition, said polar projections being capable, by rotation, of endwise ad ustment toward or from the diaphragm.

23-. In telephonic apparatus, the combination with a casing, a watertight cover therefor and ;a removable partition dividing the easing into front and rear compartments, of'a permanent magnet fixed to toe rear s1de of the partition, soft iron polar extensions extending towardthecenggr of the magnet, an internally screw thread soft iron tube carried by each of said extensions, an externally screw threaded polar projection of soft iron carried within each tube, receiver coils supported by said tubes, and a diaphragm secured to the wall of the rear compartment opposite the partition, said polar proiections being capable, by rotation, of endwise ad justment toward or from the diaphragm, and hearing means in communication with the said rear compartment.

24. Telephonic apparatus comprising a casing'of cylindrical form, a removable partition plate dividing the easing into front and rear compartments, a cover hinged to one 'end of the casing and formed with a central 0 ening, packing and securing devices for c osing the cover in a wat(, r-tight manner, a holder rigidly attached to the said cover in front of the opening therein, a stationary front carbon transmitter diaphragm and a revoluble rear carbon electrode in said holder, carbon granules confined between said diaphragm and rear electrode, a spindle extending through the rear of the holder, a. telephone switch in the front compartment, a movable member therefor, means cxtending through. thefront cover for operating the ill? switch member, means provided on i switch member for simultaneously rotating the spindle to which the movable transmitter electrode attached, a permanentmagnet fixed to the rear side of the removable par-- tition, a diaplnragm holder fixed to the rear end wallof the rear connnirtn'ient and carrying the receiver diaphragm, and a trumpet mounted to revolve about a horizontal axis and having its inlet end opposite said re ceiver diaphragm. I 25. Telephonic apparatus comprising a.

, casing of cylindrical form, a I'Gll'lOVttblO partition plate dividing the casing into front and rear compartments, a cover hinged to one end of the casing and formed with a central 0 ening, packing and securing devices for c osing the cover in. a water-tight manner, a holder rigidly attached to the said cover in front of the opening therein, a stationary front carbon transmitter diaphragm and a revoluble rear carbon electrode in said holder, carbon granules confined between va movable member therefor,

saiddiaphragm and rear electrode, a spindle extending through the rear of the holder, a telephone switch in the front compartment,

means extending through the front cover for operating the switch member, means provided on the switch member for simultaneously rotating the spindle to which the movable transmitter electrode is attached, a permanent magnet fixed to the rear side of the removable partiftion, soft iron polar extensions extending towardthe center of the magnet, an internally screw threaded soft iron tube carried by each of said extensions,.- an externally screw threaded polar projection of soft iron carried; Within each tube,receiver coils supported by sa d tubes, and a diaphragm secured to the y l l l l l l l wall. of the rear compartment opposite the partition, said polar pro ections being capable, by rotation. of endwise ad ustment toward or from the diaphragm.

26. Telephonic apparatus comprising a casing of cylindrical form, a removable partition plate dividing the easing into front and rear compartments, a cover hinged to one end of the casingand formed with a central opening, packing and securing devices for closing the cover in a water tight manner, a holder rigidly attached to the said'cover in frr'intof the opening therein, a stationar) front carbon transmitter diaphragm. and a revoluble rear carbon electrode in holder,.carbon granules confined between said diaphragm and rear electrode, a spindle extending through the rear of the holder, a telephone switch in the front lf()lll])ttl'tlll(lll1,

a movable member therefor, means extend ing through the front cover for operating the switch member, means provided on the switch member for slmullz'tneously rotating the spindle to which the-movable transmitter electrode s attached, a permanent magnet fixed-to the rear side of the removable partition, soft iron polar extensions extending toward the center of the magnet, an internally screw threaded soft iron tube carried by each of said extensions, an externally screw threaded polar projection of soft iron carried within each tube, receiver coils supported by said tubes, and a diaplnagnisecured to the wall of the rear compartment opposite the partition, said polar projec' tions being capable, by rotation, of endwise ad ,iustment toward or from the diapl'iragm, and a trumpet mounted to revolve about a horizontal axis and having its inlet end oppo site the receiver diaphragm.

27. Telephonie apparatus comprising a casing of cylindricalform, a removable partition plate dividing the casing into front and rear compartments, cover. hinged to one end of thecasingand formed with a central ,0 )cning, packing and securing devices for closing the cover in a Water-tight manner, a holder rigidly attached to the said cover in front of the opening therein, a stationary front carbon transmitter diaphragm and a revoluble rear carbon electrode. in said holder, carbon granules confined between said diaphragm and rear electrode, a spindle extending through the rear of the holder, a telephone switch in the front compartment, a movable member therefor, means extending through the front cover for operating the switch member, means provided on the switch member for simultaneously rotating the spindle to which the movable transmitter electrode is attached, a set of contacts station'arily carried by the removable artition on the side adjacent to the front 0 iambers and a co-acting'set of contacts on the inner side of the cover arranged to automatically said 1 

